The phrase "bring down to Chinatown" is often used informally to mean to give someone a lesson or to clarify a misunderstanding, usually in a straightforward manner. It may imply a sense of roughness or directness when addressing an issue, or that you will take someone to the place (Chinatown) to understand something better.
The phrase likely originates from cultural references to Chinatown, which is often associated with vibrant life and authentic cultural experiences. The informal use of "bring down to Chinatown" suggests a place where one might gain wisdom or insight through direct experience.